Question

The two ends of a metal rod are maintained at temperatures $100{}^{\circ }C$ and $110{}^{\circ }C$ . The rate of heat flow in the rod is found to be $4.0{\text{J s}}^{-1}$ . If the ends are maintained at temperatures $200{}^{\circ }C$ and $210{}^{\circ }C$ , the rate of heat flow will be:

• A. $44.0{\text{J s}}^{-1}$
• B. $16.8{\text{ J s}}^{-1}$
• C. $8.0{\text{ J s}}^{-1}$
• D. $4.0{\text{ J s}}^{-1}$

Answer 1

Answer: (D)

In case I, temperature difference between the ends of rod is $=110-100=10^{o}C$
In case II, temperature difference between the ends of rod is $=210-200=10^{o}C$
Hence, in both the case temperature difference are same i.e. $10^{o}C$
$\therefore$ Rate of heat flow is also $4J{s}^{-1}$ in both the cases.